TY - JOUR
T1 - The spectrum of mutations in the PCFT gene, coding for an intestinal folate transporter, that are the basis for hereditary folate malabsorption
AU - Zhao, Rongbao
AU - Sang, Hee Min
AU - Qiu, Andong
AU - Sakaris, Antoinette
AU - Goldberg, Gary L.
AU - Sandoval, Claudio
AU - Malatack, J. Jeffrey
AU - Rosenblatt, David S.
AU - Goldman, I. David
PY - 2007/8/15
Y1 - 2007/8/15
N2 - Hereditary folate malabsorption (HFM) is a rare autosomal recessive disorder caused by impaired intestinal folate absorption and impaired folate transport into the central nervous system. Recent studies in 1 family revealed that the molecular basis for this disorder is a loss-of-function mutation in the PCFT gene encoding a proton-coupled folate transporter. The current study broadens the understanding of the spectrum of alterations in the PCFT gene associated with HFM in 5 additional patients. There was no racial, ethnic, or sex pattern. A total of 4 different homozygous mutations were detected in 4 patients; 2 heterozygous mutations were identified in the fifth patient. Mutations involved 4 of the 5 exons, all at highly conserved amino acid residues. A total of 4 of the mutated transporters resulted in a complete loss of transport function, primarily due to decreased protein stability and/or defects in membrane trafficking, while 2 of the mutated carriers manifested residual function. Folate transport at low pH was markedly impaired in transformed lymphocytes from 2 patients. These findings further substantiate the role that mutations in PCFT play in the pathogenesis of HFM and will make possible rapid diagnosis and treatment of this disorder in infants, and prenatal diagnosis in families that carry a mutated gene.
AB - Hereditary folate malabsorption (HFM) is a rare autosomal recessive disorder caused by impaired intestinal folate absorption and impaired folate transport into the central nervous system. Recent studies in 1 family revealed that the molecular basis for this disorder is a loss-of-function mutation in the PCFT gene encoding a proton-coupled folate transporter. The current study broadens the understanding of the spectrum of alterations in the PCFT gene associated with HFM in 5 additional patients. There was no racial, ethnic, or sex pattern. A total of 4 different homozygous mutations were detected in 4 patients; 2 heterozygous mutations were identified in the fifth patient. Mutations involved 4 of the 5 exons, all at highly conserved amino acid residues. A total of 4 of the mutated transporters resulted in a complete loss of transport function, primarily due to decreased protein stability and/or defects in membrane trafficking, while 2 of the mutated carriers manifested residual function. Folate transport at low pH was markedly impaired in transformed lymphocytes from 2 patients. These findings further substantiate the role that mutations in PCFT play in the pathogenesis of HFM and will make possible rapid diagnosis and treatment of this disorder in infants, and prenatal diagnosis in families that carry a mutated gene.
UR - http://www.scopus.com/inward/record.url?scp=34548026299&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34548026299&partnerID=8YFLogxK
U2 - 10.1182/blood-2007-02-077099
DO - 10.1182/blood-2007-02-077099
M3 - Article
C2 - 17446347
AN - SCOPUS:34548026299
SN - 0006-4971
VL - 110
SP - 1147
EP - 1152
JO - Blood
JF - Blood
IS - 4
ER -